What is the clearance required between discharge piping and a water supply line?

The requirement for a clearance of at least 1 inch between discharge piping and a water supply line is based on preventing contamination of the potable water supply. This distance is crucial to ensure that any potential discharge or drainage systems do not introduce contaminants into the drinking water lines. By maintaining this 1-inch clearance, you create a physical separation that helps mitigate the risk of backflow or leaching of pollutants from the discharge system into the clean water supply. This guideline is generally adopted in plumbing codes to safeguard public health and ensure compliance with standards designed to protect potable water systems.